(a) Field of the invention
The present invention concerns an apparatus for quantitatively metering granular materials such as powders and particles of synthetic resins for use as starting materials, pigments, cement, fertilizers and foodstuffs.
(b) Description of the prior art
As apparatuses of this type, there is known an apparatus comprising a main body having a plurality of independent metering compartments having upper and lower open ends and disposed radially around an axis, and top and bottom end plates adapted for covering said upper and lower open ends of the compartments and being rotatable about this axis, the top end plate having a hole adapted for being brought into alignment with the upper open end of each compartment as this end plate is rotated, the bottom end plate having a hole so positioned as is not aligned with the hole of the top end plate and being adapted for being brought into alignment with the lower open end of each compartment as this end plate is rotated, so that, with the rotation of these end plates, a material requiring metering is fed into the compartments successively through the hole of the top end plate, and the metered material contained in the compartments is allowed to flow out through the hole of the bottom end plate from one compartment after another. However, such known metering apparatus has the disadvantage that the granular material requiring metering enters into a small space formed between the trailing edge of the hole of the top end plate through which the material is fed into the metering compartment and the uppermost wall edge of a partition wall which defines adjacent metering compartments, resulting in hampering the smooth rotation of the end plates.